bsnes/snesreader/unrar/coder.cpp

// #included by unpack.cpp
#ifdef RAR_COMMON_HPP

inline unsigned int RangeCoder::GetChar()
{
	return(UnpackRead->GetChar());
}


void RangeCoder::InitDecoder(Unpack *UnpackRead)
{
	RangeCoder::UnpackRead=UnpackRead;

	low=code=0;
	range=uint(-1);
	for (int i=0;i < 4;i++)
		code=(code << 8) | GetChar();
}


#define ARI_DEC_NORMALIZE(code,low,range,read)                           \
{                                                                        \
	while ((low^(low+range))<TOP || range<BOT && ((range=-low&(BOT-1)),1)) \
  {                                                                      \
    code=(code << 8) | read->GetChar();                                  \
    range <<= 8;                                                         \
    low <<= 8;                                                           \
  }                                                                      \
}


inline int RangeCoder::GetCurrentCount()
{
	return (code-low)/(range /= SubRange.scale);
}


inline uint RangeCoder::GetCurrentShiftCount(uint SHIFT)
{
	return (code-low)/(range >>= SHIFT);
}


inline void RangeCoder::Decode()
{
	low += range*SubRange.LowCount;
	range *= SubRange.HighCount-SubRange.LowCount;
}
#endif